What is the significance of the first item of Article 18 of the Three Gorges Project Immigration Regulations? Why do local regulations allow one floor and not two floors?

According to the Three Gorges Project Construction Regulations:

Eighteenth rural residential relocation should be in accordance with the resettlement plan, according to the preparation of new residential construction planning. The construction planning of new residential areas should be adapted to local conditions, which is beneficial to production and life.

Infrastructure such as roads, water supply and power supply in newly-built residential areas shall be organized by townships (towns) and villages.

Housing demolition compensation funds are contracted to households in accordance with rural housing compensation standards, and immigrants are used for housing construction.

When immigrants build houses, they can build houses separately or in a unified way on a voluntary basis. Relevant local people's governments and villagers' committees shall not enforce building standards.

It is obviously against the regulations for local governments to enforce building standards.